| In the hypersonic flow the air is compressed strongly and a strong bow shockwave will form in front of the aircraft. Behind the shock wave, the velocity of air isdecelerated greatly and a large amount of kinetic energy carried by the air isconverted to heat energy. The aircraft compassed by the hot air suffers seriousaerodynamic heating problem. An opposing jet can change the structure of the flowfield and reduce the aerodynamic heating effectively. A numerical study of the flowfield with opposing jet is carried out in this thesis.Firstly, numerical simulation of the hypersonic flow with opposing jet isstudied and the result of calculation is compared to the experimental data to ensurethe feasibility of the simulation. Then the influence on the aerodynamic heatingcharacteristics in two different flow modes via changing the parameters of the jet isstudied separately and the parameters include temperature, pressure and velocity ofthe jet. Then the influence of the angle of attack is analyzed in the3D flow field.Secondly, the study of the hypersonic flow with chemical non-equilibriumreaction is carried out. Without opposing jet, the result of the fluid characteristics inchemical non-equilibrium model is compared with the one in the perfect gas model.Then with interference of the opposing jet, the flow of high Mach number withchemical reactions is studied under different jet parameters.Finally, the optimization of aerodynamic heating reduction is studied afterbuilding an optimal model. The parameters of opposing jet are optimized by theGenetic Algorithms in two cases that both the total pressure and temperature arefixed and the mass rate of jet is fixed, and the purpose is to improve theaerodynamic characteristics of blunt body. |
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